Surfactant Drag Reduction Caused by a Cationic Surfactant with Excess Addition of Counter-ions
Surfactant Drag Reduction Caused by a Cationic Surfactant with Excess Addition of Counter-ions
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DOI：
10.1252/jcej.37.1232
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发表时间：
2004-10
影响因子：
0.8
通讯作者：
H. Usui;T. Kamada;Hiroshi Suzuki
中科院分区：
文献类型：
--
作者：
H. Usui;T. Kamada;Hiroshi Suzuki
表面活性剂减阻技术是一种很有前途的降低区域供冷供热系统泵功率的技术。许多研究报道对减阻现象给出了明确的前景。然而，表面活性剂的减阻机理和表面活性剂胶束的微观结构仍然是未知的。本研究旨在为反离子对胶束结构的影响以及表面活性剂在管流中的减阻作用提供实验依据。本文作者一直在研究阳离子表面活性剂与合适的抗衡离子（水杨酸钠）的表面活性剂减阻。反离子的阳离子表面活性剂的摩尔比的效果进行了讨论，使用在湍流管流中的减阻，胶束的大小和剪切稀化增稠粘度的实验结果。这些实验结果表明，一个新的减阻状态存在于非常高的反离子与表面活性剂的摩尔比。这种新的状态给出了显着的减阻，但显示出非常弱的粘弹性。产生强粘弹性的最佳摩尔比为（表面活性剂）：（抗衡离子）= 1：1.5，但在更高的摩尔比下，拉伸粘度降低，同时保持高的减阻效率。胶束结构在较高的反离子摩尔比下会发生变化，但这种新的结构也可能是有效的减阻。
Surfactant drag reduction is a promising technology to reduce the pumping power of district heating–cooling systems. Many investigations have been reported to give a clear prospect of the drag-reducing phenomenon. However, the mechanism of surfactant drag reduction and the microstructure of surfactant micelles are still left unknown. This study aims to provide an experimental evidence of the effect of counter-ions on the micelle structure and the surfactant drag reduction in a pipe flow. The present authors have been investigating the surfactant drag reduction with a cationic surfactant with suitable counter-ions (sodium salicylate). The effect of the molar ratio of the counter-ion to the cationic surfactant is discussed using the experimental results on the drag reduction in a turbulent pipe flow, on the micelle size and on the shear thinning–thickening viscosity. These experimental results suggest that a new drag-reducing state exists at very high molar ratios of the counter-ion to the surfactant. This new state gives a remarkable drag reduction, but shows very weak viscoelasticity. The optimum molar ratio to cause a strong viscoelasticity is (surfactant):(counter-ion) = 1:1.5, but at higher molar ratios, the elongational viscosity decreases, while high drag reduction effectiveness is kept. The micelle structure could be changed at higher counter-ion molar ratio, but this new structure may also be effective for drag reduction.